Azimuth Quadrupole Spectra derived from 2.76 TeV Pb-Pb PID Differential v₂(p_t) Data

2025/12/13 by T. A. Trainor, Trainor, Thomas A.
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Particle Detector Development and Performance

paper · pdf · doi:10.48550/arxiv.2512.12159

Abstract

v₂(p_t) data are intended to estimate the amplitude of an azimuth component of particle spectra interpreted as representing elliptic flow of a dense QCD medium. As defined, v₂(p_t) is a ratio with a single-particle spectrum appearing in its denominator. Its numerator represents a spectrum Fourier component arising from a boosted particle source. The Cooper-Frye (CF) formalism may be used to describe emission from a boosted source. CF analysis reveals that the v₂(p_t) numerator includes a factor p_t in the boost frame with major consequences for data interpretation. A unique quadrupole p_t spectrum may be isolated from v₂(p_t) data and compared directly with the single-particle spectrum in the v₂ denominator and with hydro theory. A monopole boost (aka radial flow) value may be estimated from v₂(p_t) data. Several novel results emerge via the Cooper-Frye analysis.

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